How can a person or an object gain energy?
How can a person or an object gain energy?
If an object is moving, it is said to have kinetic energy (KE). Potential energy (PE) is energy that is “stored” because of the position and/or arrangement of the object. The classic example of potential energy is to pick up a brick. When you pick it up, you apply force and lift the object.
How does force relate to energy?
Bigger pushes and pulls cause bigger changes in an object’s motion or shape. When objects collide, contact forces transfer energy so as to change the objects’ motions. When two objects interact, each one exerts a force on the other, and these forces can transfer energy between them.
Does more force mean more energy?
And since the nail will move in the same distance, the force will be more when energy is more. Since energy is changed to work done, and the distance will be constant, the only variable is the force.
How do we say that work is done on an object?
When a force acts on an object over a distance, it is said to have done work on the object. Physically, the work done on an object is the change in kinetic energy that that object experiences.
Do we say work is done?
Work is done whenever the given conditions are satisfied: A force acts on the body. There is a displacement of the body caused by the applied force along the direction of the applied force. The work W is equal to the force f times the distance d, or W = fd
Why do we say work is done?
Work is said to be done when a force moves an object through a distance in its own direction.
Why do we say work done against gravity is negative?
Direction of force in a gravity is always towards the centre of earth. And the direction of displacement is against the force exerted by the gravity. So both the force and displacement is in opposite direction. So the work done is negative
How is work done?
Work done via force (F) is equal to the change in kinetic energy….
- m = the mass of the object measured using kilograms.
- W = the work done by an object measured using Joules.
- vf = the final velocity of an object measured using m/s.
- vi = the initial velocity of an object measured using m/s.
When the work is said to be done?
Work is said to be done when there is change in the position of the object due to the force applied on it
What happens when work is done?
Work changes the amount of mechanical and internal energy possessed by objects. When work is done on a system or object, energy is added to it. When work is done by a system or object, it gives some of its energy to something else. Throwing a ball means a hand applies a force as an arm swings forward
Under what conditions work done is zero?
Zero work is done when the displacement of a body is zero or perpendicular (θ=900,cosθ=0) to the direction of force applied, then work done is zero. For example, if a person tries to push a wall, he is applying force yet the wall does not move, so the displacement of the wall is zero, and hence work done is zero.
What are the two conditions when work done is zero?
Two conditions when the work done is zero are: (i) When there is no displacement (S=0) and, (ii) When the displacement is nonual to the direction of the force (θ=90o).
Under what condition the work done by a force is zero * 1 point?
In physics, work done is actually always with the aspect of an external agent which is known to produce a force on some other entity. The work is stated as zero when there is no displacement of any given object along a line of force
Which work done is maximum?
Hence work done is maximum when θ is at zero degree.
Can work done be negative?
Work can be either positive or negative: if the force has a component in the same direction as the displacement of the object, the force is doing positive work. If the force has a component in the direction opposite to the displacement, the force does negative work.1999. okt. 8.
Under what conditions the work done is maximum and minimum?
If the applied force is in one direction and the displacement of the body is in the opposite direction, then work done is minimum as COS 180 is equal to minus one. This is the minimum possible work done and work done is maximum when force and displacement are in the same direction
What is the minimum work done when a 65 kg?
The minimum work needed would be done by a force acting upward, in the opposite direction of the weight. Its magnitude would have to be greater than the weight, so >65 kg*9.8m/s^2 as you did. You wrote w=fd, where w is the work, f is the force and d is the distance
What should be the value of theta to get maximum positive work?
The angle between force and displacement for i) Minimum Work and ii) Maximum Work should be. The angle between force and displacement should be θ = 90° for minimum work. The angle between force and displacement should be θ = 0° for maximum work.
What are the characteristics of maximum work?
The conditions for maximum work are as follow: All the changes taking place in the system during the process are reversible. All the changes taking place in the system during the process should take place in infinitesimally small infinite steps.
In which gas work done is maximum?
Solution : The work done by a gas is maximum when it expands isobarically.
What is the work energy theorem?
The work-energy theorem states that the net work done by the forces on an object equals the change in its kinetic energy.
Why is reversible work maximum?
Reversible processes produce the maximum amount of work If a process does work on the surroundings, you get more work out of the process if it is done slowly. This is because less heat is lost to the surroundings. So a reversible process (infinitely slow) does the maximum work.
Which work is more reversible or irreversible?
And as the condition completely exists in reversible case, Reversible process has greater work done than irreversible process
What is special about a reversible process?
(a) For a reversible process, the forward and reverse change occurs by the same path. In a reversible process both the system and the surroundings are restored to their original condition by exactly reversing the change.
Which is reversible process?
A reversible process is defined as a process in which the system and surroundings can be returned to the original conditions from the final state without producing any changes in the thermodynamics properties of the universe, if the process is reversed. From: Pressure Retarded Osmosis, 2017.
What is meant by irreversible process?
What are Irreversible Processes? An irreversible process can be defined as a process in which the system and the surroundings do not return to their original condition once the process is initiated.